- 0xetc:
something else,
such as programming languages other than C, such as Go, C++, Rust...
- data-*:
directories beginning with `data` are ones NOT PRIMARILY related to
io devices. such as:
process, memory, data structure, algorithms...
- dev-*:
directories beginning with `dev` are ones PRIMARILY related to
io devices. such as:
network devices, disks, serials...
- k*:
directories beginning with `k` are ones PRIMARILY related to
linux kernel
- var-*:
directories beginning with `var` are ones NOT PRIMARILY related to
any of above